A heartbeat mechanism is widely used on Internet applications on a mobile phone. For example, the heartbeat mechanism is used on an Android native application, QQ, microblog, and WeChat. The mobile phone regularly sends short information (which may be referred to as heartbeat information or a heartbeat package) to an application server. With the heartbeat mechanism for the Internet applications, the application server may push information related to a mobile phone user in a timely manner, such as a short message, an image, or a voice in WeChat. Once the application server cannot receive heartbeat information of the mobile phone, the server may take over a service of the mobile phone, so as to avoid service stagnation. In some scenarios, a service data packet of an Internet application has a relatively small throughput. The same is true for an answer (ACK) message at an uplink Transmission Control Protocol (TCP) layer.
In addition, as communications technologies develop, communication is no longer performed only between human and human, and machine to machine (M2M) communication (machine type communication, MTC) becomes increasingly popular. It is predicted that 50 billion machines will be connected to each other by using the communications technologies by 2020. In the MTC, software and hardware are combined, so that various data information such as road conditions, health data of a patient, a temperature or a humidity of a specified place can be monitored in real time and regularly reported, thereby implementing intelligent management between machines.
Uplink data packets such as a heartbeat packet and a data packet in the MTC are discontinuous and have a relatively small throughput. Particularly, a heartbeat package of an Internet application on a mobile phone has a relatively long period. For example, a heartbeat period of an old version of QQ is 30 s, a heartbeat period of a new version of QQ is 180 s, a heartbeat period of WeChat is 300 s, and a heartbeat period of a Google native application is about 1680 s. As a result, a terminal device (such as a mobile phone or a terminal device in the MTC) that sends such type of data packets enters a radio resource control (RRC) idle state or a state of out of uplink synchronization with a base station. Once the terminal device enters the RRC idle state or the state of out of uplink synchronization, a large amount of signaling needs to be consumed to perform uplink data packet transmission. A current Long Term Evolution (LTE) network is mainly designed for transmission of discontinuous data packets with a large throughput.
FIG. 1A and FIG. 1B are respectively schematic diagrams of uplink data packet transmission in an LTE network by a terminal device that is in an RRC idle state and a terminal device that is in a state of out of uplink synchronization.
As shown in FIG. 1A, for the terminal device that is in the RRC idle state, for example, a user equipment (UE), random access needs to be first completed by performing step 101 and step 102, then an RRC connection needs to be established by performing step 103 to step 105, and then a base station, for example, an evolved NodeB (eNB), provides non-access stratum (NAS) information and RRC reconfiguration information to the UE respectively by performing step 106 and step 107. Finally, the UE sends an uplink data packet by performing step 108.
In FIG. 1B, for a UE that is in a state of out of uplink synchronization, a random access process also needs to be first completed by performing step 111 and step 112. A random access response (RAR) in step 112 carries a synchronization instruction, for example, a timing advance (TA) instruction. Then, in step 113, the UE sends a scheduling request (SR) or a buffer status report (BSR) to the eNB. After receiving a scheduling grant (SG) sent by the eNB in step 114, the UE finally sends the uplink data packet in step 115.
It can be learned that in the current LTE network, for the terminal device that is in the RRC idle state or in the state of out of uplink synchronization, signaling exchange needs to be performed between the terminal device and the base station eNB for multiple times before the terminal device sends uplink data. For example, random access or establishment of an RRC connection needs to be completed by means of signaling exchange. However, for the foregoing discontinuous service data packets with a relatively small throughput, if the foregoing method is used to transmit uplink data, resource utilization is relatively low, and power consumption is relatively high. In addition, as Internet applications and MTC become popular, a large quantity of terminal devices periodically send the heartbeat packet or such type of data packets, causing network congestion and even a signaling storm.